Astrophysics & Astrophotography

Dr. Travis A. Rector

NGC 5426/7

Like two skaters grabbing hands while passing, the two galaxies NGC 5427 (lower left) and its twin NGC 5426 (upper right), are beginning a collision that could take a hundred million years to complete. Already a bridge-like feature has begun to form between the galaxies. This intergalactic bridge acts like a feeding tube, allowing the twins to share gas and dust with one other across the 60,000 light years of space separating them. The collision may have also triggered bursts of star formation inside each galaxy. The star-forming, or HII, regions appear as hot pink knots that trace out the spiral patterns in each galaxy. HII regions are common to many spiral systems, but the giant ones in NGC 5426 are curiously knotted and more abundant on the side of the galaxy closest to NGC 5427. Despite their appearance in this two-dimensional image, NGC 5426s western (top) spiral arm is the one closest to us, as opposed to NGC 5427s southeastern (bottom) arm. NGC 5426 is also the closer of the two galaxies.